Deciding how to cut water demand is a matter for all of us

This big, needy city of Sydney is exhausting its rivers. What's needed is a new way of thinking - about our water supply and the decision-making processes that enable us to live within our means.

The historical approach of the water industry was based on a simple premise. If demand rose, new dams and pipelines were built. If water ran out in one catchment, it was taken from the next. When water was piped into houses, offices and factories, it came out as sewage which needed expensive treatment and disposal.

This "supply-side" thinking is pervasive and has led to an over-investment in the supply of water and to an under-investment in reducing demand. One of the water industry's best-kept secrets is this: it is cheaper, faster and less environmentally damaging to pay customers to save water rather than to supply it. This is the basis of "demand-side" thinking, which provides the biggest gains at the lowest cost.

Sydney already has a per capita demand less than most Australian cities, and the investment by Sydney Water in demand reduction represents one of the largest programs in the world. Still, there is significant potential for efficiency improvements. These are technical as well as behavioural. Technical fixes include: improved toilets, showerheads, taps, cooling towers, urinals, washing machines, irrigation equipment and fixing leaks. Behavioural changes include improvements in garden design and maintenance. The cost of an even larger investment in these measures is minuscule compared with the cost of a river collapsing, the cost of emergency supplies in a drought and the cost of reduced community services because too much was spent on dams and pipelines.

The responsibility to turn this situation around falls on a number of shoulders, not just those of customers or Sydney Water. For example, while the US has had standards which regulate the efficiency of water-using equipment since 1994, federal and state environment ministers in Australia agreed only recently to introduce compulsory labelling. By itself this will be inadequate. The existing NSW Water Conservation Strategy, which would lead, among other initiatives, to best-practice water efficiency in government buildings, remains unfunded.

A stable source of funds is needed to reduce demand and repair the damage and this should be linked to the volume of water taken from the environment. A "healthy river surcharge" in the range of 5 to 20 cents per kilolitre would probably be sufficient.

Sydney's rising population and enormous growth in housing is increasing water demand, yet the way in which new developments are provided with water, sewerage and drainage hasn't changed for more than 100 years. Water has been piped into housing developments from distant sources and the sewage drained and pumped away, through leaking pipes, to a distant sewage treatment plant for discharge to the nearest waterways.

This will need to change. New developments and buildings should have appliances and landscapes that offer best-practice efficiency in water use and reduce demand by more than 40 per cent. Rainwater can be captured and wastewater treated and recycled in a decentralised way - rather than using drinking-quality water to flush toilets and water lawns. These strategies can reduce the net water demand and sewage discharge by more than 80 per cent.

New decision-making methods are needed. Policy makers, elected representatives, experts and NGOs have their role in supporting good decision making.

However, many of these decisions are not technical - they are about values. Citizens can make these judgements. For example, the reliability of our water supply system and how often water restrictions are applied are matters for public consideration, not the realm of experts. Citizens may be prepared to trade off Sydney's 97 per cent water supply reliability, higher than most other cities, for healthier rivers.

Who should pay for a healthy river? High water users? All city dwellers? These decisions require informed citizens to deliberate on issues of some complexity. Sound unusual? It's a growing trend in some countries, and now in Australia, to use methods that combine random selection of citizens to increase representativeness, with deliberative techniques, to help make complex public policy decisions.

Including citizens in decision making could be just one of the ways that will bring forward a new way of thinking in providing urban water services.

And after that, who knows? Perhaps electricity and urban transport could follow?

Professor Stuart White is director of the Institute for Sustainable Futures, University of Technology, Sydney.